The Use of Additive Manufacturing to Fabricate Structural Components for Wearable Robotic Devices

2015 ◽  
Author(s):  
Ray Churchwell ◽  
Kevin W. Hollander ◽  
Connor Theisen
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Fused Deposition Modeling ◽  
Joint Torque ◽  
Human Gait ◽  
Structural Components ◽  
Average Force ◽  
Fused Deposition ◽  
3D Printed ◽  
Robotic Devices

Our interest is in designing, fabricating and testing wearable robotic devices that assist human gait of able bodied individuals [1, 2]. Recently, we have been experimenting with Additive Manufacturing, 3D printing, using Fused Deposition Modeling technology as a method to fabricate key structural components for these robotic devices. A key structural component for the JTAR (Joint Torque Augmentation Robot) hip exoskeleton was manufactured using 3D printing and has been destructively tested to validate design requirements, the average force required to destroy the part was 2500 N with a standard deviation of 86 N, and this level of strength provided a safety factor in excess 4 times the expected load. The 3D printed part also has been successfully demonstrated on the JTAR robot for approximately 32 kilometers of hiking with no signs of degradation. The JTAR device has been demonstrated with the 3D printed hip mechanism in various environments, including treadmills and unconstrained outdoor environments.

Biodegradable 3D Printed Polymer Microneedles for Transdermal Drug Delivery

2018 ◽  
Author(s):  
Michael A. Luzuriaga ◽  
Danielle R. Berry ◽  
John C. Reagan ◽  
Ronald A. Smaldone ◽  
Jeremiah J. Gassensmith
Keyword(s):  
Drug Delivery ◽  
3D Printing ◽  
Transdermal Drug Delivery ◽  
Fused Deposition Modeling ◽  
Fused Deposition ◽  
Modeling Software ◽  
Deposition Modeling ◽  
3D Printed ◽  
Microfabrication Technique ◽  
Mechanical Strengths

Biodegradable polymer microneedle (MN) arrays are an emerging class of transdermal drug delivery devices that promise a painless and sanitary alternative to syringes; however, prototyping bespoke needle architectures is expensive and requires production of new master templates. Here, we present a new microfabrication technique for MNs using fused deposition modeling (FDM) 3D printing using polylactic acid, an FDA approved, renewable, biodegradable, thermoplastic material. We show how this natural degradability can be exploited to overcome a key challenge of FDM 3D printing, in particular the low resolution of these printers. We improved the feature size of the printed parts significantly by developing a post fabrication chemical etching protocol, which allowed us to access tip sizes as small as 1 μm. With 3D modeling software, various MN shapes were designed and printed rapidly with custom needle density, length, and shape. Scanning electron microscopy confirmed that our method resulted in needle tip sizes in the range of 1 – 55 µm, which could successfully penetrate and break off into porcine skin. We have also shown that these MNs have comparable mechanical strengths to currently fabricated MNs and we further demonstrated how the swellability of PLA can be exploited to load small molecule drugs and how its degradability in skin can release those small molecules over time.

scholarly journals Mechanical Characterization and Thermodynamic Analysis of Laser-Polished Landscape Design Products Using 3D Printing

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2601
Author(s):  
Yue Ba ◽  
Yu Wen ◽  
Shibin Wu
Keyword(s):  
Surface Roughness ◽  
3D Printing ◽  
Fused Deposition Modeling ◽  
High Surface ◽  
Landscape Design ◽  
Laser Polishing ◽  
Fused Deposition ◽  
Design Structure ◽  
3D Printed ◽  
Stability And Accuracy

Recent innovations in 3D printing technologies and processes have influenced how landscape products are designed, built, and developed. In landscape architecture, reduced-size models are 3D-printed to replicate full-size structures. However, high surface roughness usually occurs on the surfaces of such 3D-printed components, which requires additional post-treatment. In this work, we develop a new type of landscape design structure based on the fused deposition modeling (FDM) technique and present a laser polishing method for FDM-fabricated polylactic acid (PLA) mechanical components, whereby the surface roughness of the laser-polished surfaces is reduced from over Ra 15 µm to less than 0.25 µm. The detailed results of thermodynamics and microstructure evolution are further analyzed during laser polishing. The stability and accuracy of the results are evaluated based on the standard deviation. Additionally, the superior tensile and flexural properties are examined in the laser-polished layer, in which the ultimate tensile strength (UTS) is increased by up to 46.6% and the flexural strength is increased by up to 74.5% compared with the as-fabricated components. Finally, a real polished landscape model is simulated and optimized using a series of scales.

scholarly journals 3D Printed Clamps for In Vitro Tensile Tests of Human Gracilis and the Superficial Third of Quadriceps Tendons

2021 ◽  
Vol 11 (6) ◽  
pp. 2563
Author(s):  
Ivan Grgić ◽  
Vjekoslav Wertheimer ◽  
Mirko Karakašić ◽  
Željko Ivandić
Keyword(s):  
3D Printing ◽  
Fused Deposition Modeling ◽  
Tensile Tests ◽  
Biomechanical Properties ◽  
Testing Procedure ◽  
Laboratory Equipment ◽  
Fused Deposition ◽  
Custom Made ◽  
3D Printed

Recent soft tissue studies have reported issues that occur during experimentation, such as the tissue slipping and rupturing during tensile loads, the lack of standard testing procedure and equipment, the necessity for existing laboratory equipment adaptation, etc. To overcome such issues and fulfil the need for the determination of the biomechanical properties of the human gracilis and the superficial third of the quadriceps tendons, 3D printed clamps with metric thread profile-based geometry were developed. The clamps’ geometry consists of a truncated pyramid pattern, which prevents the tendons from slipping and rupturing. The use of the thread application in the design of the clamp could be used in standard clamping development procedures, unlike in previously custom-made clamps. Fused deposition modeling (FDM) was used as a 3D printing technique, together with polylactic acid (PLA), which was used as a material for clamp printing. The design was confirmed and the experiments were conducted by using porcine and human tendons. The findings justify the usage of 3D printing technology for parts manufacturing in the case of tissue testing and establish independence from the existing machine clamp system, since it was possible to print clamps for each prepared specimen and thus reduce the time for experiment setup.

Design, Development and Characterization of Linear, Soft Actuators via Additive Manufacturing

2018 ◽  
Author(s):  
Alfonso Costas ◽  
Daniel E. Davis ◽  
Yixian Niu ◽  
Sadegh Dabiri ◽  
Jose Garcia ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Fused Deposition Modeling ◽  
Single Step ◽  
Design Development ◽  
Initial Attempt ◽  
Fused Deposition ◽  
Piston Cylinder ◽  
Compact Size ◽  
Soft Actuators

Additive manufacturing has emerged as an alternative to traditional manufacturing technologies. In particular, industries like fluid power, aviation and robotics have the potential to benefit greatly from this technology, due to the design flexibility, weight reduction and compact size that can be achieved. In this work, the design process and advantages of using 3D printing to make soft linear actuators were studied and highlighted. This work explored the limitations of current additive manufacturing tolerances to fabricate a typical piston-cylinder assembly, and how enclosed bellow actuators could be used to overcome high leakage and friction issues experienced with a piston-cylinder type actuator. To do that, different 3D printing technologies were studied and evaluated (stereolithorgraphy and fused deposition modeling) in the pursuit of high-fidelity, cost-effective 3D printing. The initial attempt consisted of printing the soft actuators directly using flexible materials in a stereolithography-type 3D printer. However, these actuators showed low durability and poor performance. The lack of a reliable resin resulted in the replacement of this material by EcoFlex® 00-30 silicone and the use of a 3D printed mold to cast the actuators. These molds included a 3-D printed dissolvable core inside the cast actuator in order to finish the manufacturing process in one single step. An experimental setup to evaluate the capabilities of these actuators was developed. Results are shown to assess the steady-state and the dynamic characteristics of these actuators. These tests resulted into the stroke-pressure and stroke-time responses for a specific load given different proportional valve inputs.

scholarly journals Effect of Porosity on Mechanical Properties of 3D Printed Polymers: Experiments and Micromechanical Modeling Based on X-Ray Computed Tomography Analysis

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1154 ◽  
Author(s):  
Wang ◽  
Zhao ◽  
Fuh ◽  
Lee
Keyword(s):  
Computed Tomography ◽  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Fused Deposition Modeling ◽  
Micromechanical Model ◽  
Micromechanical Modeling ◽  
X Ray ◽  
Fused Deposition ◽  
3D Printed ◽  
X Ray Computed

Additive manufacturing (commonly known as 3D printing) is defined as a family of technologies that deposit and consolidate materials to create a 3D object as opposed to subtractive manufacturing methodologies. Fused deposition modeling (FDM), one of the most popular additive manufacturing techniques, has demonstrated extensive applications in various industries such as medical prosthetics, automotive, and aeronautics. As a thermal process, FDM may introduce internal voids and pores into the fabricated thermoplastics, giving rise to potential reduction on the mechanical properties. This paper aims to investigate the effects of the microscopic pores on the mechanical properties of material fabricated by the FDM process via experiments and micromechanical modeling. More specifically, the three-dimensional microscopic details of the internal pores, such as size, shape, density, and spatial location were quantitatively characterized by X-ray computed tomography (XCT) and, subsequently, experiments were conducted to characterize the mechanical properties of the material. Based on the microscopic details of the pores characterized by XCT, a micromechanical model was proposed to predict the mechanical properties of the material as a function of the porosity (ratio of total volume of the pores over total volume of the material). The prediction results of the mechanical properties were found to be in agreement with the experimental data as well as the existing works. The proposed micromechanical model allows the future designers to predict the elastic properties of the 3D printed material based on the porosity from XCT results. This provides a possibility of saving the experimental cost on destructive testing.

scholarly journals EFFECT OF EXTRUSION PROCESS PARAMETERS ON MECHANICAL PROPERTIES OF 3D PRINTED PLA PRODUCT

2021 ◽  
Vol 6 (2) ◽  
pp. 119
Author(s):  
Nanang Ali Sutisna ◽  
Rakha Amrillah Fattah
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Fused Deposition Modeling ◽  
Extrusion Process ◽  
Experimental Procedure ◽  
Fused Deposition ◽  
Novel Approach ◽  
Deposition Modeling ◽  
3D Printed ◽  
3D Digital Models

The method of producing items through synchronously depositing material level by level, based on 3D digital models, is named Additive Manufacturing (AM) or 3D-printing. Amongs many AM methods, the Fused Deposition Modeling (FDM) technique along with PLA (Polylactic acid) material is commonly used in additive manufacturing. Until now, the mechanical properties of the AM components could not be calculated or estimated until they've been assembled and checked. In this work, a novel approach is suggested as to how the extrusion process affects the mechanical properties of the printed component to obtain how the parts can be manufactured or printed to achieve improved mechanical properties. This methodology is based on an experimental procedure in which the combination of parameters to achieve an optimal from a manufacturing experiment and its value can be determined, the results obtained show the effect of the extrusion process affects the mechanical properties.

Incorporation of fluorescent quantum dots for 3D printing and additive manufacturing applications

2018 ◽  
Vol 6 (28) ◽  
pp. 7584-7593 ◽  
Author(s):  
Cole D. Brubaker ◽  
Talitha M. Frecker ◽  
James R. McBride ◽  
Kemar R. Reid ◽  
G. Kane Jennings ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Additive Manufacturing ◽  
3D Printing ◽  
Quantum Dot ◽  
Fused Deposition Modeling ◽  
Fused Deposition ◽  
Cadmium Sulfur Selenide ◽  
Functionalized Materials ◽  
Deposition Modeling ◽  
Manufacturing Applications

3D printing of cadmium sulfur selenide quantum dot functionalized materials compatible with fused deposition modeling type processes and applications.

scholarly journals Experience of implementation in educational process modern technologies of FDM 3D printing

2021 ◽  
pp. 55-59
Author(s):  
Petr Andrienko ◽  
Vladimir Vasilevskij ◽  
Ivan Vittsivskyi
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Fused Deposition Modeling ◽  
Current Transformer ◽  
Educational Process ◽  
Small Scale ◽  
Thermoplastic Material ◽  
Fused Deposition ◽  
Deposition Modeling ◽  
Modern Technologies

Fused Deposition Modeling is an additive manufacturing technology where a temperature-controlled head extrudes a thermoplastic material onto a build platform in a predetermined path. Standard, advanced thermoplastics and composites are used for printing. Among the areas of application for FDM printing, the main ones are rapid prototyping, as well as small-scale and batch production. The purpose of the work is the implementation of FDM 3D printing technology in the educational process of students in specialty 141 "Electroenergy, electrotechnics and electromechanics". The features of the technology of additive manufacturing of electrical apparatuses parts by the method of FDM printing have been investigated. Parts of four standard sizes were printed using ABS + and PLA plastics, namely, current transformer carcasses in the amount of 110 pieces and sensor bodies in the amount of 100 pieces. For printing, an FDM 3D printer was used built on the XZ Head Y Bed kinematic scheme with an open working chamber. The analysis of defects in finished products was carried out, which showed that the main defects are deviations of the actual dimensions and geometric shape of the finished products. Ways to prevent the occurrence of these defects are considered, namely, correcting the size of the model at the stage of preparing the model for printing, minimizing the filling density of the model, using brims in models, setting the optimal temperature of the working platform and simultaneously printing several products. The results of the study o features of the technology of additive manufacturing of electrical apparatuses parts by the method of FDM printing made it possible to develop a set of laboratory works for students of the specialty 141 "Electroenergy, electrotechnics and electromechanics".

Vibration Characteristics of 3D Printed Viscoelastic Graded Polymeric Plates

2021 ◽  
Author(s):  
Justin Carter ◽  
Kumar Vikram Singh ◽  
Fazeel Khan
Keyword(s):  
3D Printing ◽  
Fused Deposition Modeling ◽  
Polymeric Materials ◽  
Vibration Characteristics ◽  
Thin Plates ◽  
Future Research ◽  
Structural Components ◽  
Processing Technologies ◽  
Fused Deposition ◽  
Multiple Materials

Abstract The exploration of structures made of multiple materials is a growing area of research as additive manufacturing processing technologies such as fused deposition modeling (FDM) 3D printing allows for their fabrication. Such a technology allows for rapid prototyping of structural components with complex geometries or spatially distributed materials with different properties and functionalities. By selecting suitable spatial distribution of materials, the performance of structural components can be manipulated and enhanced as per different engineering application needs. For a low-cost design of structural prototypes using 3D printing processes, viscoelastic polymeric materials are often used, having inherent damping properties. In this research, vibration characteristics of thin plates which are axially graded with multiple polymeric materials are investigated. The goal is to understand the influence of material grading on the frequency and damping characteristics of graded plates. Although in literature, material grading along the thickness in designing composite laminates and their vibration characteristics are available, the performance of plates having axially graded viscoelastic polymers have not been investigated yet. Through systematic modeling and experimental plans, vibration characteristics of axially graded viscoelastic plates are presented here. In particular, the damping performance for different grading schemes is evaluated. It is anticipated that such analysis will allow accurate modeling and testing of design prototypes of structural components for future research, such as design and testing of graded panels for enhanced flutter characteristics.

scholarly journals 3D-Printable PP/SEBS Thermoplastic Elastomeric Blends: Preparation and Properties

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 347 ◽  
Author(s):  
Shib Banerjee ◽  
Stephen Burbine ◽  
Nischay Kodihalli Shivaprakash ◽  
Joey Mead
Keyword(s):  
3D Printing ◽  
Carbon Black ◽  
Computer Aided Design ◽  
Fused Deposition Modeling ◽  
Mechanical Performance ◽  
Polymeric Materials ◽  
Fused Deposition ◽  
3D Printed ◽  
Injection Molded ◽  
Preferential Location

Currently, material extrusion 3D printing (ME3DP) based on fused deposition modeling (FDM) is considered a highly adaptable and efficient additive manufacturing technique to develop components with complex geometries using computer-aided design. While the 3D printing process for a number of thermoplastic materials using FDM technology has been well demonstrated, there still exists a significant challenge to develop new polymeric materials compatible with ME3DP. The present work reports the development of ME3DP compatible thermoplastic elastomeric (TPE) materials from polypropylene (PP) and styrene-(ethylene-butylene)-styrene (SEBS) block copolymers using a straightforward blending approach, which enables the creation of tailorable materials. Properties of the 3D printed TPEs were compared with traditional injection molded samples. The tensile strength and Young’s modulus of the 3D printed sample were lower than the injection molded samples. However, no significant differences could be found in the melt rheological properties at higher frequency ranges or in the dynamic mechanical behavior. The phase morphologies of the 3D printed and injection molded TPEs were correlated with their respective properties. Reinforcing carbon black was used to increase the mechanical performance of the 3D printed TPE, and the balancing of thermoplastic elastomeric and mechanical properties were achieved at a lower carbon black loading. The preferential location of carbon black in the blend phases was theoretically predicted from wetting parameters. This study was made in order to get an insight to the relationship between morphology and properties of the ME3DP compatible PP/SEBS blends.

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